Police in Madrid received phone calls from alarmed bystanders on Friday telling them that two masked gunmen had bundled a victim into a black Mercedes in the upmarket Madrid neighbourhood of Salamanca.
The story was published in Spanish daily El Mundo on Sunday and read on Monday morning by 37-year- old IT worker José Manuel Conde.
He told reporters that he immediately thought, "Shit, that's my stag party!"
The unusual party pickup was the idea of José's friend, David who was helped by a third man.
"We had to see how to get him there (to the party) and I had the idea of the kidnapping," he explained.
"We parked the car and the first thing we did was put on our balaclavas."
David claims that they explained to various people in the area what they were doing while they waited for José to finish work.
He said that most people were laughing.
"Someone else must have seen us from a distance and misinterpreted it."
The duo seized their friend, who is due to get married on the 27th of July, covered his head with a bag and threw him in the trunk of the car.
"He believed it for about 20 minutes, he was scared, then he started laughing."
"When I read the news in El Mundo I freaked out a bit," said David.
He phoned the police who didn't see the funny side of the story and insisted that David visit the station where he was warned that it had been "a dangerous game".